A method and system for processing digital image data taken from a three-dimensional topographic area including terrain and a right of way including a first and a second object to establish a clearance surface to define clearance violations within a boundary area. Waypoints are located to define a centerline and the boundary area to be analyzed. Vegetation coordinate points in the scene are determined from the digital image data. Ground coordinate points are determined from the digital image data. A clearance surface segment is constructed within the boundary area between the first and second object. The clearance surface is determined from the location of the first and second object and clearance criteria. The clearance surface is used to define a violation region.